2 * vim:ts=4:sw=4:expandtab
4 * i3 - an improved dynamic tiling window manager
5 * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
17 #include <cairo/cairo-xcb.h>
18 #include <pango/pangocairo.h>
20 static const i3Font *savedFont = NULL;
22 static xcb_visualtype_t *root_visual_type;
23 static double pango_font_red;
24 static double pango_font_green;
25 static double pango_font_blue;
27 static PangoLayout *create_layout_with_dpi(cairo_t *cr) {
29 PangoContext *context;
31 context = pango_cairo_create_context(cr);
32 pango_cairo_context_set_resolution(context, get_dpi_value());
33 layout = pango_layout_new(context);
34 g_object_unref(context);
40 * Loads a Pango font description into an i3Font structure. Returns true
41 * on success, false otherwise.
44 static bool load_pango_font(i3Font *font, const char *desc) {
45 /* Load the font description */
46 font->specific.pango_desc = pango_font_description_from_string(desc);
47 if (!font->specific.pango_desc) {
48 ELOG("Could not open font %s with Pango, fallback to X font.\n", desc);
52 LOG("Using Pango font %s, size %d\n",
53 pango_font_description_get_family(font->specific.pango_desc),
54 pango_font_description_get_size(font->specific.pango_desc) / PANGO_SCALE);
56 /* We cache root_visual_type here, since you must call
57 * load_pango_font before any other pango function
58 * that would need root_visual_type */
59 root_visual_type = get_visualtype(root_screen);
61 /* Create a dummy Pango layout to compute the font height */
62 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
63 cairo_t *cr = cairo_create(surface);
64 PangoLayout *layout = create_layout_with_dpi(cr);
65 pango_layout_set_font_description(layout, font->specific.pango_desc);
67 /* Get the font height */
69 pango_layout_get_pixel_size(layout, NULL, &height);
70 font->height = height;
73 g_object_unref(layout);
75 cairo_surface_destroy(surface);
77 /* Set the font type and return successfully */
78 font->type = FONT_TYPE_PANGO;
83 * Draws text using Pango rendering.
86 static void draw_text_pango(const char *text, size_t text_len,
87 xcb_drawable_t drawable, xcb_visualtype_t *visual, int x, int y,
88 int max_width, bool pango_markup) {
89 /* Create the Pango layout */
90 /* root_visual_type is cached in load_pango_font */
91 cairo_surface_t *surface = cairo_xcb_surface_create(conn, drawable,
92 visual, x + max_width, y + savedFont->height);
93 cairo_t *cr = cairo_create(surface);
94 PangoLayout *layout = create_layout_with_dpi(cr);
97 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
98 pango_layout_set_width(layout, max_width * PANGO_SCALE);
99 pango_layout_set_wrap(layout, PANGO_WRAP_CHAR);
100 pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
103 pango_layout_set_markup(layout, text, text_len);
105 pango_layout_set_text(layout, text, text_len);
108 cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
109 cairo_set_source_rgb(cr, pango_font_red, pango_font_green, pango_font_blue);
110 pango_cairo_update_layout(cr, layout);
111 pango_layout_get_pixel_size(layout, NULL, &height);
112 /* Center the piece of text vertically. */
113 int yoffset = (height - savedFont->height) / 2;
114 cairo_move_to(cr, x, y - yoffset);
115 pango_cairo_show_layout(cr, layout);
118 g_object_unref(layout);
120 cairo_surface_destroy(surface);
124 * Calculate the text width using Pango rendering.
127 static int predict_text_width_pango(const char *text, size_t text_len, bool pango_markup) {
128 /* Create a dummy Pango layout */
129 /* root_visual_type is cached in load_pango_font */
130 cairo_surface_t *surface = cairo_xcb_surface_create(conn, root_screen->root, root_visual_type, 1, 1);
131 cairo_t *cr = cairo_create(surface);
132 PangoLayout *layout = create_layout_with_dpi(cr);
134 /* Get the font width */
136 pango_layout_set_font_description(layout, savedFont->specific.pango_desc);
139 pango_layout_set_markup(layout, text, text_len);
141 pango_layout_set_text(layout, text, text_len);
143 pango_cairo_update_layout(cr, layout);
144 pango_layout_get_pixel_size(layout, &width, NULL);
147 g_object_unref(layout);
149 cairo_surface_destroy(surface);
155 * Loads a font for usage, also getting its metrics. If fallback is true,
156 * the fonts 'fixed' or '-misc-*' will be loaded instead of exiting. If any
157 * font was previously loaded, it will be freed.
160 i3Font load_font(const char *pattern, const bool fallback) {
161 /* if any font was previously loaded, free it now */
165 font.type = FONT_TYPE_NONE;
167 /* No XCB connction, return early because we're just validating the
168 * configuration file. */
173 /* Try to load a pango font if specified */
174 if (strlen(pattern) > strlen("pango:") && !strncmp(pattern, "pango:", strlen("pango:"))) {
175 const char *font_pattern = pattern + strlen("pango:");
176 if (load_pango_font(&font, font_pattern)) {
177 font.pattern = sstrdup(pattern);
180 } else if (strlen(pattern) > strlen("xft:") && !strncmp(pattern, "xft:", strlen("xft:"))) {
181 const char *font_pattern = pattern + strlen("xft:");
182 if (load_pango_font(&font, font_pattern)) {
183 font.pattern = sstrdup(pattern);
188 /* Send all our requests first */
189 font.specific.xcb.id = xcb_generate_id(conn);
190 xcb_void_cookie_t font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
191 strlen(pattern), pattern);
192 xcb_query_font_cookie_t info_cookie = xcb_query_font(conn, font.specific.xcb.id);
194 /* Check for errors. If errors, fall back to default font. */
195 xcb_generic_error_t *error;
196 error = xcb_request_check(conn, font_cookie);
198 /* If we fail to open font, fall back to 'fixed' */
199 if (fallback && error != NULL) {
200 ELOG("Could not open font %s (X error %d). Trying fallback to 'fixed'.\n",
201 pattern, error->error_code);
203 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
204 strlen(pattern), pattern);
205 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
207 /* Check if we managed to open 'fixed' */
209 error = xcb_request_check(conn, font_cookie);
211 /* Fall back to '-misc-*' if opening 'fixed' fails. */
213 ELOG("Could not open fallback font 'fixed', trying with '-misc-*'.\n");
215 font_cookie = xcb_open_font_checked(conn, font.specific.xcb.id,
216 strlen(pattern), pattern);
217 info_cookie = xcb_query_font(conn, font.specific.xcb.id);
220 if ((error = xcb_request_check(conn, font_cookie)) != NULL)
221 errx(EXIT_FAILURE, "Could open neither requested font nor fallbacks "
222 "(fixed or -misc-*): X11 error %d",
228 font.pattern = sstrdup(pattern);
229 LOG("Using X font %s\n", pattern);
231 /* Get information (height/name) for this font */
232 if (!(font.specific.xcb.info = xcb_query_font_reply(conn, info_cookie, NULL)))
233 errx(EXIT_FAILURE, "Could not load font \"%s\"", pattern);
235 /* Get the font table, if possible */
236 if (xcb_query_font_char_infos_length(font.specific.xcb.info) == 0)
237 font.specific.xcb.table = NULL;
239 font.specific.xcb.table = xcb_query_font_char_infos(font.specific.xcb.info);
241 /* Calculate the font height */
242 font.height = font.specific.xcb.info->font_ascent + font.specific.xcb.info->font_descent;
244 /* Set the font type and return successfully */
245 font.type = FONT_TYPE_XCB;
250 * Defines the font to be used for the forthcoming calls.
253 void set_font(i3Font *font) {
258 * Frees the resources taken by the current font. If no font was previously
259 * loaded, it simply returns.
262 void free_font(void) {
263 /* if there is no saved font, simply return */
264 if (savedFont == NULL)
267 free(savedFont->pattern);
268 switch (savedFont->type) {
272 case FONT_TYPE_XCB: {
273 /* Close the font and free the info */
274 xcb_close_font(conn, savedFont->specific.xcb.id);
275 free(savedFont->specific.xcb.info);
278 case FONT_TYPE_PANGO:
279 /* Free the font description */
280 pango_font_description_free(savedFont->specific.pango_desc);
288 * Defines the colors to be used for the forthcoming draw_text calls.
291 void set_font_colors(xcb_gcontext_t gc, color_t foreground, color_t background) {
292 assert(savedFont != NULL);
294 switch (savedFont->type) {
298 case FONT_TYPE_XCB: {
299 /* Change the font and colors in the GC */
300 uint32_t mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND | XCB_GC_FONT;
301 uint32_t values[] = {foreground.colorpixel, background.colorpixel, savedFont->specific.xcb.id};
302 xcb_change_gc(conn, gc, mask, values);
305 case FONT_TYPE_PANGO:
306 /* Save the foreground font */
307 pango_font_red = foreground.red;
308 pango_font_green = foreground.green;
309 pango_font_blue = foreground.blue;
315 * Returns true if and only if the current font is a pango font.
318 bool font_is_pango(void) {
319 return savedFont->type == FONT_TYPE_PANGO;
322 static int predict_text_width_xcb(const xcb_char2b_t *text, size_t text_len);
324 static void draw_text_xcb(const xcb_char2b_t *text, size_t text_len, xcb_drawable_t drawable,
325 xcb_gcontext_t gc, int x, int y, int max_width) {
326 /* X11 coordinates for fonts start at the baseline */
327 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
329 /* The X11 protocol limits text drawing to 255 chars, so we may need
333 /* Calculate the size of this chunk */
334 int chunk_size = (text_len > 255 ? 255 : text_len);
335 const xcb_char2b_t *chunk = text + offset;
338 xcb_image_text_16(conn, chunk_size, drawable, gc, x, pos_y, chunk);
340 /* Advance the offset and length of the text to draw */
341 offset += chunk_size;
342 text_len -= chunk_size;
344 /* Check if we're done */
348 /* Advance pos_x based on the predicted text width */
349 x += predict_text_width_xcb(chunk, chunk_size);
354 * Draws text onto the specified X drawable (normally a pixmap) at the
355 * specified coordinates (from the top left corner of the leftmost, uppermost
356 * glyph) and using the provided gc.
358 * Text must be specified as an i3String.
361 void draw_text(i3String *text, xcb_drawable_t drawable, xcb_gcontext_t gc,
362 xcb_visualtype_t *visual, int x, int y, int max_width) {
363 assert(savedFont != NULL);
364 if (visual == NULL) {
365 visual = root_visual_type;
368 switch (savedFont->type) {
373 draw_text_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text),
374 drawable, gc, x, y, max_width);
376 case FONT_TYPE_PANGO:
377 /* Render the text using Pango */
378 draw_text_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
379 drawable, visual, x, y, max_width, i3string_is_markup(text));
385 * ASCII version of draw_text to print static strings.
388 void draw_text_ascii(const char *text, xcb_drawable_t drawable,
389 xcb_gcontext_t gc, int x, int y, int max_width) {
390 assert(savedFont != NULL);
392 switch (savedFont->type) {
396 case FONT_TYPE_XCB: {
397 size_t text_len = strlen(text);
398 if (text_len > 255) {
399 /* The text is too long to draw it directly to X */
400 i3String *str = i3string_from_utf8(text);
401 draw_text(str, drawable, gc, NULL, x, y, max_width);
404 /* X11 coordinates for fonts start at the baseline */
405 int pos_y = y + savedFont->specific.xcb.info->font_ascent;
407 xcb_image_text_8(conn, text_len, drawable, gc, x, pos_y, text);
411 case FONT_TYPE_PANGO:
412 /* Render the text using Pango */
413 draw_text_pango(text, strlen(text),
414 drawable, root_visual_type, x, y, max_width, false);
419 static int xcb_query_text_width(const xcb_char2b_t *text, size_t text_len) {
420 /* Make the user know we’re using the slow path, but only once. */
421 static bool first_invocation = true;
422 if (first_invocation) {
423 fprintf(stderr, "Using slow code path for text extents\n");
424 first_invocation = false;
427 /* Query the text width */
428 xcb_generic_error_t *error;
429 xcb_query_text_extents_cookie_t cookie = xcb_query_text_extents(conn,
430 savedFont->specific.xcb.id, text_len, (xcb_char2b_t *)text);
431 xcb_query_text_extents_reply_t *reply = xcb_query_text_extents_reply(conn,
434 /* We return a safe estimate because a rendering error is better than
435 * a crash. Plus, the user will see the error in their log. */
436 fprintf(stderr, "Could not get text extents (X error code %d)\n",
438 return savedFont->specific.xcb.info->max_bounds.character_width * text_len;
441 int width = reply->overall_width;
446 static int predict_text_width_xcb(const xcb_char2b_t *input, size_t text_len) {
451 if (savedFont->specific.xcb.table == NULL) {
452 /* If we don't have a font table, fall back to querying the server */
453 width = xcb_query_text_width(input, text_len);
455 /* Save some pointers for convenience */
456 xcb_query_font_reply_t *font_info = savedFont->specific.xcb.info;
457 xcb_charinfo_t *font_table = savedFont->specific.xcb.table;
459 /* Calculate the width using the font table */
461 for (size_t i = 0; i < text_len; i++) {
462 xcb_charinfo_t *info;
463 int row = input[i].byte1;
464 int col = input[i].byte2;
466 if (row < font_info->min_byte1 ||
467 row > font_info->max_byte1 ||
468 col < font_info->min_char_or_byte2 ||
469 col > font_info->max_char_or_byte2)
472 /* Don't you ask me, how this one works… (Merovius) */
473 info = &font_table[((row - font_info->min_byte1) *
474 (font_info->max_char_or_byte2 - font_info->min_char_or_byte2 + 1)) +
475 (col - font_info->min_char_or_byte2)];
477 if (info->character_width != 0 ||
478 (info->right_side_bearing |
479 info->left_side_bearing |
481 info->descent) != 0) {
482 width += info->character_width;
491 * Predict the text width in pixels for the given text. Text must be
492 * specified as an i3String.
495 int predict_text_width(i3String *text) {
496 assert(savedFont != NULL);
498 switch (savedFont->type) {
503 return predict_text_width_xcb(i3string_as_ucs2(text), i3string_get_num_glyphs(text));
504 case FONT_TYPE_PANGO:
505 /* Calculate extents using Pango */
506 return predict_text_width_pango(i3string_as_utf8(text), i3string_get_num_bytes(text),
507 i3string_is_markup(text));